RADIO FREQUENCY IDENTIFICATION (RFID) TAG(S) and SENSOR(S)

摘要

A passive radio frequency identification (RFID) sensor is provided. This passive RFID sensor includes at least one antenna, at least one processing module, and a wireless communication module. The at least one antenna has an impedance that may vary with an environment in which the sensor is placed. Additionally, the antenna impedance might be permanently changed in response to an environmental variation or an event. The at least one processing module couples to the antenna and has a tuning module that may vary a reactive component impedance coupled to the antenna in order to change a system impedance. The system impedance includes both the antenna impedance and the reactive component impedance. The tuning module then produces an impedance value representative of the reactive component impedance. A memory module may store the impedance value which may then later be communicated to an RFID reader via the wireless communication module. The RFID reader may then exchange the impedance value representative of the reactive components of impedance with the RFID reader such that the RFID reader or another external processing unit may process the impedance value in order to determine environmental conditions at the inductive loop. These environmental conditions may include but are not limited to temperature, humidity, wetness, or proximity of the RFID reader to the passive RFID sensor.

主权项

1. A passive radio frequency identification (RFID) sensor, comprising:
at least one antenna, wherein the at least one antenna has an antenna impedance, the antenna impedance operable to vary within an environment in which the antenna is placed; at least two processing modules coupled to the at least one antenna, the at least two processing modules each comprising:
a tuning module coupled to the at least one antenna, the tuning module operable to:
vary a reactive component impedance coupled to the at least one antenna in order to change a system impedance, the system impedance comprising the at least one antenna impedance and the reactive component's impedance,produce at least one impedance value representative of the reactive component's impedance;a memory module operable to store the at least one impedance value representative of the reactive component's impedance; and a wireless communication module coupled to the first processing module, the wireless communication module operable to communicate with an RFID reader, the wireless communication module operable to send the impedance value representative of the reactive component's impedance with the RFID reader.